TEMA TELECOMUNICAZIONI SRL
IP Module AA-600
MAS-AA600-REV02EN
Page 43 of 56
12. APPENDIXES
12.1. Appendix 1: Multicast Audio Streaming for announcements
In a LAN, the Multicast term indicates the possibility of distributing information to a group of terminals. Multicast
uses class D addresses ranging from 224.x.x.x to 239.x.x.x. In our case AA-600 is able to receive audio in Multicast
and reproduce it amplified. The audio can be generated from a PC software application (for example Adam or VLC)
or directly from an IP SIP phone. The received audio in streaming is useful for reproducing voice announcements,
also called "Paging". Obviously the streaming is unidirectional, in the sense that the audio stream is sent from the
source to the destination but not vice versa. Streaming audio can be sent to several terminals at the same time (all
of which have the same Multicast address) or only to specific distinct terminals (each with its own Multicast
address). Only one audio reception address can be programmed (unlike other Tema speakers which allow up to 16
multicast addresses), with its own playback volume. The audio supported by this mode is in the G.711 (aLaw or
µLaw), G722 or linear 16 bit high quality format (format used with the AD615/S device and AD696/BM microphone
base).
Example 1
In one plant there are two systems, connected to the same network switch. From a SIP phone set up or from a
microphone base with AD615/S, I make a voice announcement via Multicast at address 239.255.12.42:
All AA-600 systems will reproduce the announcement audio message. Many more devices can be connected than
those shown in the example, as there is no limit.
Example 2
In the system there are 2 systems with
different
Multicast addresses.
The phone, by selecting to send the Multicast audio to one or the other IP address, will decide which device should
send the message in streaming.
Extensiom telephone
prepared for Multicast
LAN Switch
AD639R n. 1 Multicast address
239.255.12.42
AD639R n. 2 Multicast address
239.255.12.42
AD696/BM
AD615/S
AA-600/xx
Extensiom telephone
prepared for Multicast
LAN Switch
AD639R n. 1 Multicast address
239.255.12.42
AD639R n. 2 Multicast address
239.255.12.41
AD696/BM
AD615/S
AA-600/xx
AA-600/xx
AA-600/xx
